Access to the ultrafast dynamics of molecules-laser interaction with high harmonic spectroscopy

2018 ◽  
Author(s):  
Pengfei Lan ◽  
Peixiang Lu
Keyword(s):  
High Harmonic ◽  
Ultrafast Dynamics ◽  
Laser Interaction

Using high harmonic radiation to reveal the ultrafast dynamics of radiosensitiser molecules

2016 ◽  
Vol 194 ◽  
pp. 407-425 ◽  
Author(s):  
Pierre Çarçabal ◽  
Dominique Descamps ◽  
Stéphane Petit ◽  
Yann Mairesse ◽  
Valérie Blanchet ◽  
...  
Keyword(s):  
Internal Conversion ◽  
Hydrogen Transfer ◽  
High Harmonic ◽  
Transient Signal ◽  
Ultrafast Dynamics ◽  
Cancer Treatments ◽  
Transfer Processes ◽  
Ultrafast Relaxation ◽  
Decay Signal ◽  
Photo Stability

5-Fluorouracil (5FU) is a radiosensitiser molecule routinely used in combined chemo- and radio-therapies to enhance and localize cancer treatments. We have employed ultra-short XUV pulses produced by high harmonic generation (HHG) as a pump pulse to study the dynamics underlying the photo-stability and the radiation damage of this molecule. This work shows that it is possible to resolve individual dynamics even when using unselected HH. By comparing the results with those obtained in the multiphoton absorption at 400 nm, we were able to identify the frequencies of the HH comb relevant to the recorded dynamics: HH5 and HH3. The latter excites a high-lying Rydberg state interacting with a valence state and its dynamics is revealed by a 30 fs decay signal in the parent ion transient. Our results suggest that the same photoprotection mechanisms as those conferring photostability to the neutral nucleobases and to the DNA appear to be activated: HH5 excites the molecule to a state around 10.5 eV that undergoes an ultrafast relaxation on a timescale of 30 fs due to nonadiabatic interactions. This is followed sequentially by a 2.3 ps internal conversion as revealed by the dynamics observed for another fragment ion. These dynamics are extracted from the fragment ion signals. Proton or hydrogen transfer processes are required for the formation of three fragments and we speculate that the time scale of one of the processes is revealed by a H+ transient signal.

scholarly journals High-Harmonic Inverse-Free-Electron-Laser Interaction at 800 nm

2005 ◽  
Vol 95 (19) ◽  
Author(s):  
Christopher M. S. Sears ◽  
Eric R. Colby ◽  
Benjamin M. Cowan ◽  
Robert H. Siemann ◽  
James E. Spencer ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
High Harmonic ◽  
Laser Interaction

scholarly journals Towards attosecond imaging at the nanoscale using broadband holography-assisted coherent imaging in the extreme ultraviolet

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Wilhelm Eschen ◽  
Sici Wang ◽  
Chang Liu ◽  
Robert Klas ◽  
Michael Steinert ◽  
...  
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Extreme Ultraviolet ◽  
High Harmonic ◽  
Ultrafast Dynamics ◽  
Single Shot ◽  
Spectral Bandwidth ◽  
Resolution Limit ◽  
Coherent Imaging ◽  
Large Bandwidth

AbstractNanoscale coherent imaging has emerged as an indispensable modality, allowing to surpass the resolution limit given by classical imaging optics. At the same time, attosecond science has experienced enormous progress and has revealed the ultrafast dynamics in complex materials. Combining attosecond temporal resolution of pump-probe experiments with nanometer spatial resolution would allow studying ultrafast dynamics on the smallest spatio-temporal scales but has not been demonstrated yet. To date, the large bandwidth of attosecond pulses poses a major challenge to high-resolution coherent imaging. Here, we present broadband holography-enhanced coherent imaging, which enables the combination of high-resolution coherent imaging with a large spectral bandwidth. By implementing our method at a high harmonic source, we demonstrate a spatial resolution of 34 nm in combination with a spectral bandwidth of 5.5 eV at a central photon energy of 92 eV. The method is single-shot capable and retrieves the spectrum from the measured diffraction pattern.

scholarly journals High-Harmonic Inverse Free-Electron-Laser Interaction at 800 NM

2006 ◽  
Author(s):  
C.M.S. Sears ◽  
E. Colby ◽  
B. Cowan ◽  
R.H. Siemann ◽  
J. Spencer ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
High Harmonic ◽  
Laser Interaction

scholarly journals Deep neural networks for high harmonic spectroscopy in solids

2020 ◽  
Author(s):  
Nikolai Klimkin ◽  
Misha (Mikhail) Ivanov
Keyword(s):  
Neural Networks ◽  
Quantum Dynamics ◽  
Deep Neural Networks ◽  
High Harmonic ◽  
Laser Pulses ◽  
Complete Characterization ◽  
Ultrashort Laser Pulses ◽  
Ultrafast Dynamics ◽  
Highly Nonlinear ◽  
Ultrashort Laser

Abstract Neural networks are a prominent tool for identifying and modeling complex patterns, which are otherwise hard to detect and analyse. While machine learning and neural networks have been finding applications across many areas of science and technology, their use in decoding ultrafast dynamics of quantum systems driven by strong laser fields has been limited so far. Here we use deep neural networks to analyze spectra of highly nonlinear optical response of a crystal to intense few-cycle laser pulses. We construct a deep neural network that can efficiently utilize such spectra to resolve both the complex spectral phase of ultrashort laser pulses and simultaneously reconstruct the band structure of the crystal. Our results offer a new tool for attosecond spectroscopy of quantum dynamics and also open a route to developing all-solid-state devices for complete characterization of few-cycle pulses, including their nonlinear chirp and the carrier envelope phase.

Submicron imaging in the EUV spectral range using high-harmonic radiation

2003 ◽  
Vol 104 ◽  
pp. 149-152 ◽  
Author(s):  
M. Wieland ◽  
R. Früke ◽  
T. Wilhein ◽  
U. Kleineberg ◽  
M. Pohl ◽  
...  
Keyword(s):  
Spectral Range ◽  
High Harmonic ◽  
Harmonic Radiation
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